1. Field of the Invention
This invention relates to a chair tilt and height adjustment mechanism and, more particularly, to a knee-tilt mechanism having a single lever to lock the tilt mechanism and to release a height adjusting gas cylinder.
2. Description of Related Art
Chairs having mechanisms permitting tilting of the chair backs are disclosed in U.S. Pat. Nos. to Crossman et al. 4,948,198 issued Aug. 14, 1990, Nagelkirk et al. 5,106,157 issued Apr. 21, 1992; Meiller et al. 4,743,065 issued May 10, 1988; Zund 4,832,402 issued May 23, 1989; Pergler et al. 4,375,301 issued Mar 1, 1983; and Mrotz, III 4,818,019 issued Apr. 4, 1989. Several of these chairs disclose control means to lock the chair in the upright position as well as adjust the height of the chair through cooperation with a gas cylinder. Typically, two or more levers or other control devices are used to accomplish the tasks of locking the chair in the upright position and adjusting the height of the chair. The use of two or more control mechanisms complicates the use of the chair, increases the manufacturing cost of the chair tilt mechanism, and denigrates the appearance of the chair.
Another problem with chair tilt mechanisms and particularly knee tilt mechanisms is the cost in manufacturing the load bearing member of the tilt mechanism. Chair tilt load bearing members are traditionally formed by a metal casting operation which makes these parts relatively expensive relative to metal stamping. Although metal stampings have been used in chair tilt mechanisms, they tend to be complicated, requiring many parts and not necessarily of low profile. It is desirable to maintain a low, compact profile for the chair tilt mechanisms to enhance the appearance of the chair.